Jenkins, a Republican, is stepping down because in November, she won the seat for the 2nd Congressional District of eastern Kansas.
Spokeswoman Mary Geiger also says Jenkins will be sworn in Tuesday as a member of Congress.
And incoming State Treasurer Dennis McKinney, a Democrat, is expected to take over Monday. McKinney, from Greensburg, was serving as Kansas House minority leader when Gov. Kathleen Sebelius named him last month to replace Jenkins.
Jenkins, from Topeka, served in both the Kansas House and Senate before being elected treasurer in 2002. She was re-elected in 2006.
This year, she ousted Democratic Rep. Nancy Boyda.
(Copyright 2008 by The Associated Press. All Rights Reserved.)